Hair removal in 40 hirsute women with an intense laser-like light source

ARTICLE

Women with unwanted hair growth on the face, neck and body have social and physical problems which are encountered daily in dermatological and cosmetic practices. Female patients are divided into three groups: a group of hirsute patients, who show a male pattern of hair growth due to the increased influence of androgenes on hair follicles; a group of patients with hypertrichosis which is in general a density of hair growth; and a group of patients with cosmetic concerns. The patient should be asked which type of hair removal she prefers. There are several physical methods of temporary hair removal: shaving, which does not change the quality, quantity or texture of the hair, but which gives many side-effects such as skin irritation, crusts and beard stubbles [1, 2]; hair removing gloves, which can be used several times a day and which are made of dermabrative paper [3]; bleaching hair with 6% H₂O₂, which does not remove hair but makes it invisible as there is no shadow of the beard on the upper lip and chin anymore; plucking, which is generally used for small areas and may give postinflammatory hyperpigmentation; and waxing, which lasts longer than shaving or depilatory agents [4].

Side-effects are, among others, thermal burns, folliculitis and erythema of the skin. Chemical depilatory agents include thioglycol acid, barium, sulphur compounds and antimony, which hydrolise bonds through which hairshafts are broken down [2, 3, 5].

Electrical epilation methods for hair removal are: electrolysis, thermolysis and the blend method [6, 7]. Electrical epilation has several disadvantages, such as pain, even if local anaestethics are applied. Furthermore, this method is more time-consuming and side-effects are seen, such as scars, irritation of the skin, hyper and hypopigmentation.

Surgical depilation was introduced by Bouwman in 1978, who performed a submental incision, where the subcutaneous fat was trimmed until the follicles were visible and the hair roots were cut with serrated scissors [8].

Different lasers are used for removing hair. The concept of using selective photothermolysis with laser light for hair removal was first described by Kuriloff in 1988 for pharyngo-oesophageal hair growth [9]. The Argon Laser was used for photo-epilation in the treatment of trachomatous trichiasis [10, 11] and the Neodynium Yag Laser for epilation of hair-bearing urethral grafts [12]. Dover was one of the first to succeed in showing that the Ruby laser caused selective injury to pigmented hair follicles [13]. Zaias proposed the concept of a pulsed laser for hair removal in 1991 [14]. Grossman performed another study in which she showed that the normal-mode Ruby laser pulses damage the hair follicles [15].

The other mode methods are: Alexandrit laser: 755 nm wavelength; 1 pulse mode; 20ms pulse duration, the Diodenlaser LightSheer): 800 nm wavelength; 1 pulse mode; 5-30 ms pulse duration, the Lichtblitzgerat (Ellipse^®): 600-950 nm wavelength; 1-5 pulse mode; 0.2-50 ms/Puls for pulse duration, the Nd: YAG-Laser: 1,064 nm wavelength; 1 pulse mode; 20-40 ns(q-sw.) pulse duration, and lastly the Rublaser: 694 nm wavelength; 1 pulse mode; 0.8-3.0 ms (frm) pulse duration.

It is necessary that the laser beam penetrates deep into the dermis in order to reach the hair follicles and to be selectively absorbed by melanin.

A new laser-like device, the PhotoDerm^® VL, was developed by Energy Systems Corporation (ESC) Israel mainly for the treatment of vascular lesions located deep in the skin, such as therapy resistent portwine stains, essential telangiectasia, erythrosis interfollicularis, red keloids and small varicose veins [16-23]. This treatment consists of an intense light source which emits non-coherent light with a constant spectrum between 515 and 590 nm, variable pulse times, energy ranges between 20 and 60 J/cm² and different operating modes.

Although the Photoderm^® VL is not a coherent light source, the operation principle is the same as that of lasers. The energy produced works on a specific structure in the skin without inducing much heat in the surrounding tissues. This process is called selective photothermolysis [24]. The risks of side-effects such as scar formation or hyperpigmentation are negligible as long as the right parameter settings for each individual patient are respected. It was noticed that during the treatment of vascular lesions on the face permanent hair loss in the face occurred as a side-effect of this treatment with the PhotoDerm^® VL. Case reports have been described for definitive hair removal [25].

A new device introduced after the PhotoDerm^® VL flashlamp was the Epilight^®. This device works with different wavelengths (e.g. 590, 615, 645, and 695 nm), is expected to penetrate deeper into the skin and works with higher energy and as many as five pulse modes.

This study was carried out due to our interest in treating patients with hypertrichosis and hirsutism, and because research into the use of selective photothermolysis for hair removal is nonexistent.

Materials and methods

Patients

Forty female patients were randomly chosen in the Medical Centre Maastricht, the Netherlands, the Karlsruhe Lasercentre, Germany, and the Zürich Lasercentre, Switzerland.

A careful history of abnormal hair growth was taken for each patient. When necessary, patients were sent for further investigations by an endrocrinologist or gynaecologist.

The median age of the patients was 38.1 years with a minimum of 20 and a maximum of 58 years. Patients were being divided into four different age groups: group 1: < 30 years (8 patients); group 2: < 40 years (13 patients); group 3: < 50 years (16 patients) and group 4: > 50 years (3 patients). Patients were scored in relation to their skin types, according to Fitzpatrick's classification: there was one patient with skin type 1, 24 patients with skin type 2, 13 patients with skin type 3 and 2 patients with skin type 4. Out of 40 patients, 8 had black hair, 26 brown hair, 5 blond hair and 1 mixed hair. In the group of 40 patients, 8 (20%) women had a positive family history of hirsutism, 35 (87,5%) patients had normal periods, 4 (10%) patients had irregular periods and 1 (2.5%) patient was menopausal. Fourteen (35.1%) women were using contraceptive drugs, 3 (7.5%) were being hormonally treated, 2 (5%) patients were shaving daily, and 36 (90%) were plucking daily (of which 23 (63.8%) were plucking hair for up to 5 min and 13 (36.1%) for longer than 5 min). Patients were seen and scored by two different physicians. They were asked to shave 3-4 days before treatment. They were advised to shave rather than pluck the hair or dewax and to use a sunblocker during the time of treatment. The treated area was cooled with an ice-pack afterwards and, if necessary, Zilversulfadiazine creme, Flammazine^®, (Solvay Pharma), Weesp, the Netherlands was applied. A test spot was marked beneath the left chin (with the right side as control). After one week, a month and three months, hair counts of the test spots beneath the chin were estimated on the same patients at the Medical Centre Maastricht. An estimation was used, without counting. The percentage of hair before treatment was compared to the percentage present at evaluation.

PhotoDerm^® VL

The principle of the operation of the PhotoDerm^® VL (ESC Medical Systems Ltd, Yokneam, Israel) is based on the principle of selective photothermolysis, where the light, absorbed by the specific lesion, leads to its heating to a temperature high enough to cause thermal damage (T > 80° C), sparing the epidermis and the surrounding healthy dermis. In contrast to laser systems, the PhotoDerm^® VL uses incoherent light of a broad band spectrum in the range of 500-1,200 nm. By applying different cut-off filters (515, 550, 570, 590 nm), a specific part of the shorter wavelengths (below the indicated filter) can be filtered off. The tissue penetration depth of visible light depends on the wavelength; longer wavelengths are less absorbed by the skin. Alteration of the spectral range used during PhotoDerm^® VL treatment (which is done by selecting different cut-off filters) allows for modification of the light penetration depth to match the specific target structure, i.e. vessels of different sizes and depths, hair follicles, etc. [19]. The use of different cut-off filters also allows for adjustment of the treatment parameters to the patient's skin type. Using longer filters, which control the spectrum to higher wavelengths, results in less overlap with the higher absorption coefficient of melanin, the concentration of which depends on skin type.

The pulse duration can be varied, ranging between 2 and 25 msec and should be lower than the thermal relaxation time of the target tissue, so as to avoid cooling of the lesion during the application of light energy. In order to improve the selectivity of the light to the target tissue only, the PhotoDerm^® VL also provides ­ besides a single pulse ­ series of two and three pulses, with controlled intervals between the pulses in the range of 10-500 msec. This delay allows for cooling of the epidermis.

Fluences applied by the PhotoDerm^® VL range between 3 and 90 J/cm².

The size of the PhotoDerm^® VL treatment-head (8 x 35 mm) plays an important role in improving light penetration into the tissue, since the large spot size diminishes the scattering. A cooling gel is used on the skin during PhotoDerm^® VL treatment, which allows good optical coupling of the light to the patient's skin and also allows better heat transfer from the epidermis to the cold gel.

Statistical analysis

The statistical analysis of the data was performed in a descriptive way. The data are presented as contingency tables in order to detect the association between technical and clinical parameters. Exact Fisher tests were used to evaluate the homogeneity of the tables; p-values below 0.05 are considered significant. The Pearson Coefficient interval tested the relation between hair removal and mean treatment intervals per patient.

Results

Histology

Hair shafts showed fragmentation. No focal ruptures of the follicles and no hemorrhage was found (Fig. 1). No coagulation of the surrounding dermalcollagen was seen. The replaced follicle showed new collagen formation without any sign of scarring, and capillaries were present in the new collagen formation (Fig. 2a and 2b). The control biopsies showed no changes in the follicles or the surrounding area.

Clinical observations

In the beginning of this study there was a tendency in all centres to use a single pulse as pulse mode, a pulse duration of approx. 5-6 msec, a wavelength of 590 nm for dark hairs, 550 nm for blond hair, and a fluence between 35-40 J/m². Later on, the treatment was changed to double pulses as pulse modes, with 5 msec per pulse duration and fluences between 35-40 J/m².

At the Medical Centre Maastricht the treatment intervals were as follows:

6 weeks after the first treatment, 8 weeks after the second treatment, 3 months after the third treatment, and 3-4 months after the fourth treatment.

Depending on the skin type, delays were chosen to cool the epidermis in between the pulses, e.g. for skin type 1 and 2 a delay of 10-20 msec was chosen, with a double pulse as pulse mode, for skin type 3 a delay of 30 msec was chosen, and if treating skin type 4, a delay of > 50 msec was used.

The patients experienced the treatment as the stinging of a needle, but less painful than needle epilation. Observations made from the immediate results were subsidiary to the fluences, pulse times and pulse modes. The shorter the pulse times (< 3 msec) were, the more edema and erythema was observed. Fitzpatrick skin type 1 and 2 with dark hairs showed less side-effects than skin type 3. Only 2 patients with skin type 4 were treated. As epidermal side-effects in skin type 3 and 4 we first noticed erythema. Imprints, which turned into crusts, were observed after 24 hrs and sealed off after 4-7 days. Hyperpigmentation was seen in 20% of patients; hypopigmentation was not seen at all. The skin of the neck and the upper lip was much more sensitive. Fluences were reduced about 2-3 J/cm² in the neck compared to the cheeks and chin.

Most of the time about 20% of hair disappeared after the first treatment in dark-haired individuals. Depending on the hair cycles, growth of new hair was observed. Dark hair was removed in fewer treatment sessions, compared to blond hair (Fig. 3a and 3b).

According to our experience, hair loss is proportional to the wavelength (the higher the wavelength, the more delayed the hair loss), and therefore it was mostly longer than one week.

In the Medical Centre Maastricht, treated hairs which were long enough, were plucked out from beneath the chin, as was untreated hair from the opposite side of the chin. These were subsequently compared under the microscope. The treated hair was shrunken and broken at the epidermal border and the follicle was partly damaged. The untreated hair showed a normal outer and inner root cell sheet and a normal follicle.

Clinical data

The median age of the 40 hirsute women was 38.6 years with a minimum age of 20 years and a maximum of 58 years. The median percentage of hair loss was 76.6% with a minimum of 50% and a maximum of 95% with a average of 6 treatments. The treatment data of the patients, such as haircolor, energy, wavelength, percentage of hair reduction and number of treatments, are found in Table I.

The treatment interval was 57.6 days per patient, but only data from 30 patients was available. The Pearson Coefficient interval tested the relation between hair removal and mean treatment intervals per patient. The Pearson Coefficient interval was ­ 0.55, which means that the shorter the treatment interval, the greater the hair removal reduction.

In this study we found a significant correlation between the percentage of hair loss and the number of treatments (p = 0.04) (Table II). Two out of 39 patients showed a reduction of 50% within 2 treatments. Five out of 39 women had lost 89% of hair after 7 treatments (Table II).

Furthermore a correlation was found between hair removal and needle epilation before treatment (p = 0.002) (Table IIIA). Twenty-six out of 40 (65%) patients had undergone no previous needle epilation. This group reacted much better to hair removal than the group which had experienced prior needle epilation. Moreover, a correlation was seen between the reduction of hair and the wavelength of 570 nm (p = 0.0001) and a trend was observed with wave length of 550 nm (p = 0.08). Further association was observed between hair removal and the different energy groups. Energies were separated into 5 groups (Table IIIB). A correlation was seen between hair removal and energy groups 1 (< 30 J/cm²) and 5 (46-50 J/cm²) (p = 0.04), as well as between hair removal and energy groups 2 (31-35 J/cm²) and 5 (46-50 J/cm²) (p = 0.008). This indicates that a fluence below 30 J/cm² and the fluence between 31-35 J/cm² had more effect on hair loss than higher energies, but the number of patients (three) was too small to formulate a conclusion.

There was no statistically significant correlation found between the percentage of hair reduction and the different hair colours (black, brown, blond or mixed). Furthermore, no correlation was seen between hair removal and the four age groups, nor among patients with a positive family history, contraception use or hormonal treatment (Table IIIA). No relationship was found in hair removal between skin types 2 and 3, nor was there an association between hair removal and the different times of plucking (Table IIIA) and technical data, such as pulse modes and pulse times (Table IIIB).

Discussion

In our multicentre study, in which we investigated the use of the ILS flashlamp for hair removal in hirsute women, we found a correlation between hair removal and number of treatments and needle epilation prior to treatment. Moreover, a relationship was observed between hair loss and wavelengths of 570 nm and 550 nm. Further association was seen between hair removal and two different energy groups. There was no statistically significant correlation found between the percentage of hair reduction, the number of treatments and the different hair colours (black, brown, blond or mixed). There was no relation between hair removal and the four age groups, nor among patients with a positive family history, contraception use or hormonal treatment. No correlation was found in hair removal between skin types 2 and 3, neither was there any association between hair removal and the different times of plucking and technical data, such as pulse modes and pulse times.

Previous methods such as epilation (using a needle inserted into the follicle to destroy the germinative bulb), can cause many side-effects, such as superficial crusting, erythema and scar formation with pitholes in the skin resulting in an irregular surface, especially on the upper lip and chin. If left untreated, these side-effects persist throughout the years, but they can be avoided by reducing the current [26]. In patients who experienced prior needle epilation, scar tissue is regularly found around the follicles. This would explain our finding that patients who did not have needle epilation before treatment with the flashlamp show much better results. Scar tissue limits the scattering of light, therefore less absorption of melanine in hair shafts and follicles is observed. This fact explains our finding that patients who had undergone needle epilation previously need more treatment sessions.

New methods which cause less side-effects and which are at least as efficient need to be developed. The ILS removal of hair fulfills these requirements. As shown in this study, this device causes no scars or skin infections.

Using ILS, the pigment of the hair is absorbed from the light beam, transformed into energy, then into heat. As the hair shaft is 1-2 mm long coming out of the epidermis, it may enhance the absorption of melanine and scattering throughout the dermis up to the follicle. The heat coagulates the hair follicle in the deep dermal tissue. In the early post-treatment period partial or complete coagulation necrosis takes place. This necrosis does not extend into the surrounding dermal fibrous tissue. In our study the feeding vessels and the hair erector muscles remained intact. If the dermal papil cells are completely destroyed, this will result in a complete loss of hair. Hair can come out of the same follicle if the dermal papil cells are not completely destroyed. Hair can regrow from the bulging area which is not destroyed by light and which is localized on the opposite side of the sebaceous glands.

Depending on the structure of the hair and the content of pigment, a choice of variable energy has to be made to destroy the follicle. The different pulse modes of ILS make it possible to apply higher energies, cooling the skin between each pulse, yet still generating enough heat to destroy the hair follicle. The setting has to be changed in relation to the thickness and the colour of the hair.

One of the advantages of the treatment with the ILS flashlamp is the extremely selective thermolysis leading to an intact epidermis, in contrast with the Blend method. Only in rare cases, about 15%, were lesions of the epidermis imprints observed at a treatment protocol of short-pulse times. Most of the time the epidermis remained intact. Folliculitis, which is sometimes seen with the Blend method or home epilating devices [26-28], can be avoided by using the flashlamp. No cases of folliculitis were observed in this study. One advantage of this treatment is reduced pain, as compared to needle epilation. Most patients experienced this treatment as a mild sunburn sensation lasting for several hours. Having the choice of different fluences makes it possible to treat skin appendages without damaging the epidermis. Our group of patients, divided into different energy groups, was too small to allow for the formulation of any conclusions.

Another advantage of the ILS flashlamp is its broad spectrum of wavelengths. Depending on the skin type and hair colour, a choice can be made between the range of 515 nm and 590 nm. In our study, a correlation was found between hair reduction and the wavelength of 570 nm. With this device, there are many technical factors which have an effect on hair removal, such as pulse times and pulse modes. The number of patients was too small in our study to conclude that the wavelength of 570 nm may be the best wavelength. All other technical data have to be taken into consideration as well. Depending on the colour and the thickness of the hair, different energy ranges can be used. Compared with the Blend method, the ILS flashlamp has a spot size of 1 mm and can treat skin-surfaces of 2.8 cm² per impulse. ILS is much more time-efficient and financially beneficial than the former methods, because this device offers many varieties of possible settings.

With a choice of using individual parameters for each type of hair and skin, hair can be removed in an easier manner in the near future. The ILS therapy will be more successful than the classical methods described above. A larger area can be treated and due to a good application of energy to the hair, scar formation as a result of overheating can be avoided. To adjust the exact parameters for each type of hair and skin, more investigation, including pathohistological examination of the skin up to 5 years, has to be carried out. One such follow-up study is currently being carried out in our clinic.

Our multicentre study was the first of its kind in Europe, carried out on long-time basis. The number of forty patients is too small to confirm our clinical observations. To confirm long-term results, further studies should be performed, including patients of skin type 6.

REFERENCES

1. Lynfield VL, Mac Williams P. Shaving and hair growth. J Invest Dermatol 1970; 55: 170-2.

2. Richard RN, Uy M, Meharg GE. Temporary hair removal in patients with hirsutism: a clinical study. CUTIS 1990; 45: 199-202.

3. Wagner RF Jr. Physical methods for the management of hirsutism. CUTIS 1990; 45: 319-26.

4. Richards AN, Meharg GE. Electrolytis: observations from 13 years and 140,000 hours of experience. J Am Acad Dermatol 1995; 33: 662-6.

5. Nato AJ. Chemical removal of hair. CUTIS 1986; 38: 91.

6. Scott MJ Jr., Scott MJ III, Scott AM. Epilation. CUTIS 1990; 46: 216-7.

7. Wagner RF Jr., Tonich JM, Grande DJ. Electrolysis and thermolysis for permanent hair removal. J Am Acad Dermatol 1985; 12: 441-9.

8. Hage JJ, Bouman FG. Surgical depilation from the treatment of pseudofolliculitis or local hirsutism of the face: experience in the first 40 patients. Plastic and Reconstructive Surgery 1991; 88: 446-51.

9. Kuriloff DB, Finn DG, Kimmelman CP. Pharyngooesophageal hair growth: The role of laser epilation. Otolaryngol Head Neck Surg 1988; 98: 342-5.

10. Huneke JW. Argon laser treatment for trichosis. Opthal Plast Reconstr Surg 1992; 8: 50-5.

11. Oshry T, Rosenthal G, Lifshitz T, Shani L, Yassur Y. Argon-green laser photoepilation in the treatment of trachomatous trichiasis. Opthal Plast Reconstr Surg 1994; 10: 253-5.

12. Finkelstein LH, Blatstein LM. Epilation of hair-bearing urethral grafts using the neodymium-yag surgical laser. J Urol 1991; 146: 840-2.

13. Dover JS, Margolis RJ, Polla LL, Wantanabe S, Hruza G, Parrish J, et al. Pigmented guines pig skin irradiated with Q-switched Ruby laser pulses. Morphologic and histologic findings. Arch Dermatol 1989; 125: 43-9.

14. Zaias N. Method of hair depilation. US Patent 1991; 5,059, 192.

15. Grossmann MC, Dierckx C, Farinelli W, Flotte T, Anderson R. Damage to hair follicles by normal-mode ruby laser pulses. J Am Acad Dermatol 1996; 35: 889-94.

16. Karpen M. Treating benign vascular lesions of the lower extremities: past, present and future. J Clin Laser Med and Surg 1994; 12: 111-2.

17. Goldman MP. The use of laser therapy to treat leg telangiectasia in venous disease. Phlebology Digest 1995.

18. Schroeter CA, Wilder D, Keiner M, Raulin C, Neumann H. PhotoDerm^® VL treatment of leg teleangiectasia. JEADV (suppl.) 1995; 15: W76.

19. Goldman MP, Eckhouse S. Photothermal sclerosis of leg veins. Dermatol Surg 1996; 22: 323-30.

20. Schroeter CA, Wilder D, Reineke T, Thürlimann W, Raulin C, Neumann HAM. Treatment of leg telangiectasia up to 1 mm with the PhotoDerm VL intense pulsed light source. EJD 1997; 7: 38-42.

21. Schroeter CA, Neumann HAM. An intense light source: the PhotoDerm^® VL ­ flashlamp as a new treatment possibility for vascular skin lesions. J Dermatol Surg (in press).

22. Hellwig S, Schroeter CA, Raulin C. Behandlung essentieller Teleangiektasien durch das PhotoDerm^® VL. H u G 1996; 71: 44-7.

23. Raulin C, Goldman MO, Weiss MA, Weiss RA. Treatment of adult port-wine stains using intense pulsed light therapy (PhotoDerm^® VL). J Dermatol Surg 1996; 22: 323-30.

24. Anderson RR, Parrish RR. Selective photothermolysis: precise microsurgery by selective absorption of pulse radiation. Science 1983; 220: 524-7.

25. Werner S, Schroeter C, Drosner M, Tiel H, Raulin C. Neue Möglichkeiten der Epilation durch eine hochenergetische Blitzlampe. Derm 1997; 3: 3-8.

26. Richards RN, McKenzie MA, Meharg GE. Electroepilation (electrolysis) in hirsutism. J Am Acad Dermatol 1986; 15: 693-7.

27. Trüeb RM, Elsner P, Burg G. Pseudomonas-aeruginosa-Follikulitis nach Epilation. Hautarzt 1993; 44: 103-5.

28. Wright RC. Traumatic folliculitis of the legs: a persistant case associated with use of a home epilating device. J Am Acad Dermatol 1992; 27: 771-2.